1. Field of the Invention
The present invention relates to a method for inhibiting an inflammatory response in chondrocytes, and dedifferentiation or destruction of chondrocytes by irradiating damaged chondrocytes with low-dose radiation, and a method of treating a disease of cartilage by irradiating damaged chondrocytes with low-dose radiation.
2. Description of the Related Art
From the embryological point of view, cartilage is a tissue originated from a mesoderm such as a hard hone tissue, and forms an endoskeleton along with bones. Additionally, in the case of serious cartilage damage, the bone tissues below the cartilage may also be damaged. In particular, in the case of an articular cartilage, which has no blood vessels, neurons, and lymphoid tissues, once there is damage to the cartilage, self-regeneration of the articular cartilage is difficult. Accordingly, even the slightest damage to articular cartilage may progress further and degenerate. In this regard, various medical attempts are being made in order to recover and maintain the functions of bones and cartilage tissues.
Arthritis, a representative disease caused by cartilage damage, is a kind of degenerative disease. Reportedly, arthritis occurs in about 80% of people in Korea aged 55 or older, and in almost all people aged 70 or older, and expedited development of its therapeutic treatments is currently underway. Currently available clinical methods for treating damaged areas of articular cartilage include multiple drilling, microfracture, abrasion, transplantation of periosteum or perichondrium, etc. However, their therapeutic effects are not satisfactory, and thus active studies on new methods of treatment are in progress.
Recently, a method of inducing stem cells into chondrocytes, a method of transplanting an autologous or allogeneic cartilage tissue into a cartilage damaged area, a method of transplanting a tissue or compound, which is capable of inducing cartilage, onto the surface of the cartilage damaged area, a method of regenerating cartilage by transplanting chondrocytes into the cartilage damaged area, etc., are developed, and their preclinical or clinical test results are also reported. For example, Korean Patent Application Publication No. 2010-0051294 discloses a cell aggregate-hydrogel-polymer scaffold complex useful for cartilage regeneration, in which cell aggregates of differentiated chondrocytes are dispersed in a hydrogel matrix, and the resulting hydrogel matrix is inoculated onto a polymer scaffold and the pores thereof are filled with the cell aggregate-hydrogel-polymer scaffold complex, a method for its preparation, and a composition for treating the cartilage defects and injuries comprising the same as an active ingredient. Korean Patent Application Publication No. 2010-0061605 discloses a chondrogenic differentiation method from a mesenchymal stein cell and a composition comprising chondrogenic cell for repairing disease of cartilage damage. However, these methods have various problems in that they require an excess of time for the transplanted tissues to adapt or regenerate in a new living organism, there may occur an immune rejection response in the case of a transplanted tissue, and also that the transplanted or regenerated tissue may not be accurately settled to the original cartilage site, thus causing an aftereffect such as a lumbar herniated intervertebral disc, and are thus not yet being used in practical treatments.